1. Field of the Invention
The present invention relates to hydraulic pumps, and more particularly to techniques for detecting wear of hydraulic pumps.
2. Description of the Related Art
Hydraulic pumps are used in a wide variety of equipment to provide a source of pressurized hydraulic fluid that then is controlled to operate hydraulic actuators, such as hydraulic motors and hydraulic cylinder and ram assemblies. Over time, the internal components of a pump may wear, thereby leaking fluid which decreases the magnitude of fluid flow produced by the pump. Such leakage not only slows the motion of the hydraulic actuator, it wastes power and raises the temperature of the hydraulic fluid which also are disadvantageous. Over time, the actuator operation degrades to a point where either maintenance or replacement of the pump is necessary.
It is, therefore, desirable to detect if excessive wear of a pump occurs and be able to take remedial action.
Previous techniques for determining excessive pump wear involved sensing an amount of fluid flowing through a drain outlet in the case of the pump. Because pump wear introduces metal particles into the hydraulic fluid, another method periodically measured the size and concentration of solid particles in the fluid. The noise produced by a pump also has been used to detect excessive leakage.